SC-02-12 meeting, London, 2011-05

Report of the meeting of the SC-02-12 Working Group on Audio Applications of Networks of the SC-02 Subcommittee on Digital Audio, held in London, UK., 2011-05-14.

The meeting was convened by chair R. Foss.

The agenda and the report of the previous meeting, 2010-11-05, were accepted as written.

Open Projects

AES-R10: AES standards project report - Use cases for networks in professional audio
Scope: to identify and clarify use cases for networks in professional audio applications for Recording, Live sound, and Installations

Discussion: N. Brock pointed out that the current report indicates that these are use cases for IEEE 1394 networks. The meeting agreed that this was no longer the case and that the document should be updated to expand the use cases to have relevance to all local and wide area networks. Nathan agreed to enhance the document to include use case that were particularly relevant to wide area networks, such as distributed post-production and broadcast use cases.

Development Projects

AES-X075: Liaison with IEC TC100 for IEC 61883
Scope: Prepare recommendations and assist the work of IEC TC100SC-02-12 regarding the development and maintenance of relevant parts of IEC 61883. Any assigned task group shall report project progress to SC-02-12 and shall ask SC-02-12 for its advice on content. Administrative review of the project shall follow AESSC rules.

Discussion: J. Yoshio provided a liaison report that described work done on TC100 specifications related to SC-02-12. Of particular importance to the working group are the updates relating to the A/M protocol, namely IEC 61883-6 and IEC 62574. There are two required updates relating to DTLA and generic data. These will require updates first to the A/M protocol and then IEC 61883-6. Following these updates a CDV will be submitted. IEC 62574 is a new specification relating to general channel assignment of multi-channel audio, and IEC-61883-6 will refer to this.

Discussion: There was no-one present to provide a liaison report for this project.

AES-X170: Integrated Control, Monitoring and Connection Management for Digital Audio and other Media Networks
Scope: The objective of this project is to create and standardize: 1. A set of structured Internet Protocol-based messages that can be used to control single parameters or groups of parameters, and to monitor these parameters. The parameters are associated either with typical signal processing functionality within audio devices, synchronization between such devices, or connections between such devices. 2. A mechanism for grouping of device parameters, and messages required to implement such grouping. 3. A mechanism for the control of latency within networks of audio devices, and a specification of the messages and parameters required for the control of such latency. 4. Parameter modifiers, and the messages required to create and configure such modifiers. 5. Security levels, and the messages required to set and get such levels.

Discussion: M. Yonge had done extensive work on the appropriate formatting of the core standards document. In particular he looked at issues of compactness, easy referencing, and consistency. There was discussion around the issue of the identifier list (Annex A), and that it was the role of the AES to maintain a registry of identifiers. The mechanism for this registry needs to be established. The function of the reserved identifiers was questioned, and it was clarified that manufacturers could request identifiers from the reserved set. It was agreed that Yonge and Foss would have a 'writing group' meeting over skype in order to confirm any secretariat formatting changes and to clarify the intended meaning of the standard where necessary.

AES-X192 High-performance streaming audio-over-IP interoperability
Scope: The goal is to standardize the format for audio data within IP packets. Currently there are a number of ways of transmitting uncompressed audio over IP. There are even a
number of ways of transmitting audio using RTP.

Discussion: K. Gross, the task group leader, was not present to lead this discussion; however he did previously point out an overview document on the working group document site. S. Heinzmann started the discussion by indicating that the task group had decided to break down the task into two components - a synchronization and streaming component, and a high level discovery, connection management and control component. There would probably be two documents describing these two components. G. Shay described a media-clock to wall-clock mapping scheme that he will be proposing to the task group.

Liaisons

Liaison with AVB - M. Mora, who leads this liaison was not present at the meeting. Foss gave a brief overview of the status of IEEE 1722 and IEEE 1722.1 and there was some discussion regarding the scope of IEEE 1722.1.

Liaison with ESTA: P. Nye, who leads this liaison was not present at the meeting. He had previously posted an update before the San Francisco meeting.

Liaison with MPEG - J. Grant gave a presentation of various activities related to 'Future Networks'. These are networks that go beyond what IP can do. In particular he focused on ISO PDTR 29181, and sketched a future scenario where AVB is used for local area networking, where there are two wide area services - a synchronous low latency service and a best effort service, and where there is a single control protocol. Grant has uploaded his presentation to the working group document site.

Liaison with IEC 62379 - Unfortunately time was up before P. Stevens could present a IEC 62379 report. Foss requested that he provide a status report on the working group reflector.

New projects

There were no further projects.

New business

There was no new business.

The next meeting will be scheduled in conjunction with the AES 131th Convention, in New York, 2011-10.